


The Scientific Method

by Zelos



Series: A Splintered Tomorrow [2]
Category: Captain America (2011), Iron Man (Movies), Marvel (Movies), Marvel Avengers Movies Universe, The Avengers (2012)
Genre: Allies, Community: avengerkink, Friendship, Gen, Gen Fic, Male Friendship, Prompt Fic, Twisted and Fluffy Feelings, Unethical experiments, World War II, in the name of science, testing the limits, torture if you squint
Language: English
Status: Completed
Published: 2012-06-14
Updated: 2012-06-14
Packaged: 2017-11-07 17:30:43
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,406
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/433634
Author URL: https://archiveofourown.org/users/Zelos/pseuds/Zelos
Summary: <blockquote class="userstuff">
              <p>Written for a prompt on <a href="http://avengerkink.livejournal.com/6021.html?thread=10087301#t10087301">Avengerkink</a>:</p><blockquote>
  <p>I read a fic the other day that mentioned how they know that Captain America's metabolism is 4 times faster, that he is 800% more resistant to drugs, etc etc. I want a fic that explores how they know that. It's up to anon whether to set it in the 1940s or the present, but I'd love to see Steve being experimented on, how long he can run, how he reacts to different drugs and poisons, how long he can go without food, etc. </p>
</blockquote><p>“I am <i>not</i> experimenting on Rogers, you wretched bastard,” Howard snarled back. “He's a good man, a <i>soldier</i>, not a <i>lab rat.</i>”</p><p>“The man volunteered to be part of an experimental procedure, Stark, so in that sense he already <i>is</i> a lab rat.”</p>
            </blockquote>





	The Scientific Method

**Author's Note:**

> All I have to say in self-defense is that I envision Howard as an earlier version of Tony (adjusted as appropriate to the times), and Tony is most definitely a certified expert in chemistry, biology, anatomy, and similar subjects to have been able to develop, say, the Extremis armour.
> 
> ...*runs away*

“ _No_. Not only no, but _hell fucking no_.” Howard's utterly outraged voice carried easily through the closed double doors, well surpassing a shout. “And in case it didn't sink in, NO.”

“I'm not _asking_ you, Stark,” General Raynor's voice was low and silky and Steve heard it as easily as he did Howard's tirade, which was kind of the point, he supposed. “I'm _telling_ you to.”

“You can't _tell_ me to do anything,” Howard growled, and by this point he was up in Raynor's face, quite possibly with his hands in the general's shirt. Steve tensed, wondering if he should intervene. “I'm a _civilian_ consultant.”

“And Rogers is a _military_ asset,” the man countered. “We made him who he is now, but just who he _is_ is anyone's guess. I would have preferred to ask the late Dr. Erskine to undertake this task – understandably distasteful to you – but the good doctor is dead, and we have neither his notes nor his words to tell us what Captain America is capable of. You are the next best pick, for obvious reasons – for one, you can actually reason your way out of a paper bag.”

“I am _not_ experimenting on Rogers, you wretched bastard,” Howard snarled back. “He's a good man,a _soldier_ , not a _lab rat_.”

“The man volunteered to be part of an experimental procedure, Stark, so in that sense he already _is_ a lab rat.”

“You try to do this, old man,” Howard's voice had gone cold and full of promise, “and I will not only guarantee your political, reputational, and possibly personal demise, I will extract myself from the military's service. How well will you do, I wonder, without Stark weaponry in the hands of your soldiers?”

“Not well. Do you really want that on your conscience, Stark?” The general's voice was as sharp as a whipcrack, now. Still calm, though. Definitely a man who'd been around the block. “A quarrel with me will lead you to condemn an army of men? Good men and women, good soldiers all, and you would damn them to massacre at the Nazis' hands, because you can't get over your _personal feelings_?”

Howard did not respond immediately, and for a long moment, all Steve could hear was the quiet of his and the general's breathing, and the seething rasp of Howard's fury.

General Raynor fell silent for a moment, then continued, “The man is the only successful super soldier that we have, and as a _military asset_ , we need to know of his capabilities and weaknesses. He is not _human_ , Stark – not a normal one anyway. We've already seen that he is capable of jumping great distances and healing dire injuries. A blow that would fall a man doesn't even faze him. This is not to treat him as a _lab rat_ , as you so crudely put it; this is to discern his capabilities so we don't accidentally send him to his death by putting him in a situation even the Serum can't bail him out of.”

“I'm an engineer, not a scientist,” Howard said stiffly.

“I need you to be neither for this task. Truth be told, if you refuse, I will simply get a lowly lab tech to administrate the poisons and write the numbers. But you actually have two brain cells to rub together, Stark, and you participated in Project Rebirth. Not only would you have a better idea of what to look for, Rogers would probably prefer that it came from your hands.”

“I think Rogers would prefer the exact opposite.” Howard burst out of the room, flinging open the double doors so hard they crashed resoundingly against the wall. He'd barely taken two steps before he spotted Steve, sitting quietly in the corner.

Steve rose to his feet, and Howard froze in place. His pupils contracted as he flinched, ever so slightly, at Steve's approach. “Rogers. Ah...you heard us.”

“I did, he replied.

“Rogers?” The general stepped into the room before Steve could say anything else, his eyes and voice cool. “You ready?”

Steve hesitated only for a moment before he nodded, snapping to a crisp salute. “Yes sir.”

 

 

“You're sure about this?” Howard muttered as he readied his materials, scalpels, pistols and chemicals.

“Yeah. He had a point,” Steve offered, and Howard stared at him incredulously. “I mean, about the testing my capabilities part. Obviously we can't test for _everything_ , but the more we know, the better.”

“Spoken like a true soldier. He says 'jump', you say 'how high',” Howard sighed, shaking his head. “You're either incredibly brave or a damned fool, I can't tell which.”

“Maybe both,” he admitted, and for all his talk Steve was feeling anything but brave. “Just, uh, promise me something, okay?”

“Whatever you want, pal. What is it?”

“Don't tell anyone. Especially not Bucky or Peg – Agent Carter.” Steve smiled ruefully as Howard swabbed his arm with alcohol. “They'd go ballistic.”

“And rightly they should,” Howard replied, before he carefully slid the needle home.

 

 

He didn't have the same amount of free time that he did while being a touring monkey dressed in tights, but he was still a captain, _the_ Captain in fact, and the _super soldier_ to boot. It was easy to exclude Bucky and most everyone by passing off his disappearances as pulling rank, sensitive meetings and whatnot. For Peggy and Colonel Phillips' cases, they cited checkups for the super soldier that were not privy to outside observers. The latter wasn't even a complete lie.

And really, most of it wasn't even that bad. Didn't even take that long for the vast majority of them. It was probably harder on Howard than on him, sometimes - “run until you drop” meant that Howard had to, well, keep up.

Under Howard's watchful eyes and appropriately obfuscated medical attention, they cobbled together a set of detailed notes and data, written in Howard's precise, blocky script.

 

 

_Subject is capable of extreme muscular endurance due to the lack of buildup of fatigue poisons. He is capable of lifting masses in excess of 1200 pounds, and sustaining a top speed of approximately 50 mph for 30 minutes._

 

“You are very useful to our underequipped, underfunded troops,” Howard remarked wryly, sitting on a nearby rock. “Also, I can't believe they don't have a goddamn car jack.”

Steve smiled but did not answer directly. He slid easily under the military Jeep, sparing a quick glance at the blown wheel. “You gonna patch this?”

“Later, yeah. Just help me get the spare on, would you?”

Taking a deep breath, Steve braced his hands on the underside of the car and _pushed_ , neatly lifting the front of the car about two feet off the muddy ground before holding it steady.

“Bloody _hell_ ,” Howard muttered, a note of wonder threaded through his voice. The man apparently hadn't _really_ believed Steve when he said he could lift it, but lift it he did, without so much as a quiver.

Sighing, Howard made quick work of the nuts with his cross wrench. Five minutes later, the spare wheel was on its well; after a thumbs-up from Howard, Steve settled the vehicle carefully onto the muddy ground and slid out from underneath it.

“You didn't even break a sweat,” Howard accused. And true enough, only Steve's military fatigues looked the worse for wear. Steve brushed dirt clods out of his hair, shrugging.

Shaking his head, Howard threw the wrench into the back and hopped into the driver's seat. “All right. Thanks pal. Now,” he cocked an eyebrow at Steve as he revved the engine, “race ya back to camp.”

 

_Subject's brain capacity has increased approximately 240%, in correspondence to its increased mass. This has resulted in enhanced memory, cognitive ability, reflexes, and perceptibility to sensory stimuli._

 

“3...2...1...all right, eyes closed!” Howard called, and Steve obligingly squeezed his eyes shut. “Under enemy fire, soldier! Move, move, move!”

Steve threw himself sideways and behind a tree. Howard noted that even “blind”, he never even came close to hitting his head on the trunk. Nor did any of Howard's “fire” come even close to grazing the man as Steve dodged from tree to tree, bush to bush.

He wasn't about to tell him that though. “Still under fire!” he called, as he continued to chuck small rocks in Steve's direction haphazardly.

“I know!” Steve yelled back, flinging his shield upwards and dodging behind a rock. A heartbeat later, he'd yanked out his pistol and fired.

Silence.

Howard sighed, then stepped away from his safe vantage point, dropping his stash of rocks. The three red cardboard targets he had hung on the treetops had all fallen, one via a precisely placed bullet, the other two cut by the perfect arc drawn by the vibranium discus (which Steve idly caught).

“Mother of god,” he said, and Steve cracked open one eye to grin at him. “Rogers, what's the furthest level of education you've completed?”

“...I dropped out of high school,” Steve admitted uneasily, grin falling off his face. “Me and Bucky, we were both orphaned and I didn't...” he trailed off as he realized Howard's face held not a trace of scorn, but rueful admiration.

“Jesus, and you can do all this? Just in your head?” A grin unfurled on the engineer's face. “Y'know, when we're done with this damn war, come visit my place. I'll teach you calculus and physics and we'll make cars that _fly._ ”

 

_Subject has enhanced metabolic functions, to an approximation of 400% increase in metabolic rate compared to the average human adult. This includes all iterations of catabolism and anabolism, affecting the efficiency of his digestion, respiration, molecular syntheses, cellular division, and speed of which he recovers from injury or fatigue._

 

“You, my friend, eat like a horse. Eat like five horses, rather, and shit just as much,” Howard informed Steve genially over the latter's late breakfast.

Steve snorted though his mouthful of food – his third meal of the day, and it's not even noon yet – and gave Howard a baleful look. “It's not usually an issue on rations.”

“Yeah, I know. And you've bulked up more, lifted more mass, and heal faster now that you're not on rations. Damn, it must be like perpetually _starving_ yourself...” Howard wandered over to Steve's left side, rolled up his sleeve. “How're those cuts from yesterday?”

“Healed, pretty much. Picked out the sutures from the first one yesterday evening. They didn't make a difference, the other one healed fine without.”

“And those had been incisions of...” Howard checked his notes, made a couple of scribbles. “1.25 inch length and 0.75 inch depth.” He picked up the knife, its blade etched with gradation lines to measure incision depth. He wasn't smiling now. “Ready for the next?”

Steve nodded, but his eyes were on the small pistol lying on the end of the table. “Bring it.”

 

_Subject is approximately 340% more vulnerable than the average adult to the effects of starvation and dehydration, due to the roughly equivalent stomach capacity but extremely enhanced metabolism. As with anyone, he would catabolize his own body for energy, but he would perish far quicker than a theoretical average human with his build._

 

They'd told Phillips and his men that Steve'd gone off for a scouting mission of some sort – orders from top brass.

Steve wished he really did go on said scouting mission, even solo, because bullets would probably hurt less. The world was spinning like an endless kaleidoscope and he was so weak, so weak that he couldn't get up, couldn't get to the toilet; he'd just wet himself instead if he had to urinate.

It didn't matter, anyway – he'd guzzled the water to sate the hunger at first, but even that had stopped filling him and he'd given up, hadn't drank in ages. Time passed by in a white-walled blur and all he remembered were vague snatches of Howard's visits, when he'd help him up and weigh him and calculate body fat percentage and mumble about how much weight he'd lost.

The first round – dehydration – he'd barely lasted three days (so he was told later). Now it could've been three years for all he knew; time ceased to have meaning in a blank locked room and it's just white walls and hunger, hunger, hunger until he stopped feeling hungry and his body just ate itself from the inside out.

When he crumpled under the muscle spasms, Howard was immediately by his side, and the last thing he remembered was strong hands around his shoulders and a muttered “2 weeks, 3 days.”

 

_Subject is immune to drug intoxication._

 

“It's a good thing you heal so fast,” Howard remarked as he sipped his whiskey. “Because so far as I've seen, every single drug does absolutely jackshit on you.” He nudged the bottle in front of Steve, the latest in a long procession of mixed liquors. “Including the grandest of drinks, which I'm not sure is a good thing or not.”

Steve smiled against his glass. He had been soundly trying to drink his liver to an early grave for an hour nonstop now, and hasn't felt so much as a buzz. Howard was not drinking at the same rate, citing scientific and academic responsibilities; Steve thought it was because he was already drunk.

“Having second thoughts?” Howard asked suddenly, but his dark, glittering eyes belied the casual tones.

“About what?” Steve downed another glass, felt it burn in his throat.

Howard snorted. “Don't act stupid, Rogers. You're a damn sight smarter than most people in this camp, regardless of your educational pedigree.” He drained his glass, poured another. “I wouldn't think less of you if you left.” His voice was abrupt, forced.

“I know,” and Steve knew it was the truth. _In vino veritas_ , and all that.

“Hell, I won't say I'm not _curious_ , but it's one thing reading numbers off a page and another to be actually delivering your sentence.” Howard eyed him, grimaced. “I won't make you do this. You leave, I won't stop you. No one _can_ stop you, really. But so long as you're willing to stay, I'd rather...keep my eye on you, rather than let some halfwit undertake this...study.”

“ _I know_ , Howard,” Steve said again. But Howard wasn't going to let this drop, damn him. “But...they made me into who I am now. That science...I owe them that much. I wouldn't be up here without them. I couldn't do my part.”

“Loyal to the bone.” Howard watched him over his glass, something sarcastic and admiring in his face. “Noble and brave. Brave enough to run solo behind enemy lines, just for one man.”

Steve wanted to say that he's a man like any other, that Bucky would've done the same for him, but didn't dare in those words. “I'm just a kid from Brooklyn.”

“Not anymore. You're a hero, Rogers.” Howard laughed, bitter and triumphant, and raised his glass in salute. “To science, and the greatest hero the world will ever see.”

 _I'm no hero,_ Steve thought, but all he said was, “Cheers.”

 

_Subject is immune to terrestrial diseases, including those he was never immunized for._

 

“I amend my previous statement,” Howard declared. “Theoretically speaking drugs that don't act _on you_ should still be effective. So, painkillers, still no – pity, given your career choice – but things like antibiotics should work just fine.” He gave Steve the side eye. “Not that you really need it. Were you _really_ a sickly kid, or was the file just yanking my chain?”

“You saw me before the Serum.” Steve shrugged. “Yeah, I had everything you could think of, and probably some you can't. Asthma, scarlet fever, allergies to everything, high blood pressure, heart palpitations...”

“No vaccinations as a kid?”

“I grew up poor in Brooklyn. Food and clothes were luxuries.” Steve eyed the needle in Howard's hand. “What's that of?”

Howard gave him a thin smile that did not reach his eyes. “Smallpox.”

Steve stiffened in his seat. “Isn't that stuff...really, really bad?”

“Fatality rate varies between 10 and 75%, depending on the pock type; let's call it 30% on average.” Howard's voice was steady, but his hands were not. He tied the tourniquet messily, and swiped at Steve's arm once, twice, three times with alcohol. “I'm surprised you didn't catch it already, but if you did, I guess we wouldn't be here.” He looked like he'd rather not be here, regardless.

“But...you said I should be immune to diseases? According to Dr. Erskine's notes and your observations?”

“I think so. Let's hope I'm right.” Howard's hands steadied, drove the needle home. “That, or hope you beat the odds.”

 

_Subject is approximately 150% more resistant to the effects of oxygen deprivation. The effects of his increased efficiency of respiration is partially negated by his greater oxygen demand per unit time. When oxygen reserves are depleted, the subject's cells experience cellular death at approximately the same rate as an average human adult._

 

“Atmospheric air is approximately 21% oxygen. Expired air is approximately 14-16% oxygen for the average human adult. You, however, breathe much more efficiently,” Howard commented, not without a bit of envy. “Your expired air has an oxygen composition of approximately 5%. All the better for your metabolism and healing, I suppose. And before you ask, I haven't the faintest idea why.”

Steve grinned a little and Howard shot him a miffed look. “Detailed analyses is a luxury that neither of us can afford right now. Besides, I'm hardly the reigning expert in biochemistry and such, even if I do have a passing interest in the subject.” Howard smiled faintly at Steve's snort. “Once we're done with this damnable war I can redirect you to a couple of people I know, if you're really interested in the mechanisms of your body.”

Steve decided to not think about the possibility of more non-mandated poking and prodding. “So...I can go without oxygen longer?”

“Not quite. Sure, you wring out more oxygen from the air per breath taken, but your metabolism means that you burn it much faster too. Your lung capacity is fantastic, but you're not going to get much net gain because of your metabolism alone. It cuts both ways, soldier.” Howard shrugged, looked back at his stack of notes and scribbles. “There's a lot of factors that'd come into play. How much air you had beforehand makes a lot of difference in your oxygen reserves, particularly at your respiration efficiency. If you're in a situation involving submersion in cold water, you may trigger the diving reflex. If you've already been injured, you might go into shock. And if you do run out of oxygen, you'd die like anyone else – you heal faster because you generate more cells per given timespan, but they still need oxygen.”

Steve sighed. “So the short of it is, you don't know.”

“Not off the top of my head. But that's why we have empirical data and regression analyses.” Howard led Steve to a basin filled with water.

Steve eyed the gently steaming water with trepidation. “At least this won't hurt much, right?”

“Don't hold your breath, Captain. Actually, on second thought, do.” Howard scrounged up a towel from somewhere. “I'm told drowning is a very unpleasant experience.”

 

_Subject is resistant to mind-alteration from non-drug sources. Exact numbers unable to be acquired at this time._

 

“Seriously? They want to test my resistance to _hypnosis_?”

Howard grinned, a rare spark of amusement in his eyes. “I guess the brass is worried about someone kidnapping the Captain of America with the power of voodoo.”

Steve stared. “You're not _seriously_ going to try to hypnotize me?”

“My specialty is engineering, Captain, not woo-woo. Unless you can be wooed by my charming wit and winsome personality? No?”

 

_Subject takes approximately 305% longer to exhibit symptoms and effects of sleep deprivation, following the findings on his reaction to fatigue. The result is likely biased low as the subject was not tested under circumstances of minimal exertion. More precise numbers to be determined in the future._

 

“I could get much more precise numbers if you'd concede to a rocking chair marathon,” Howard said to Steve. “Hold still, would ya?”

“A...what? _Hey,_ ” Steve made an irritated growling noise in the back of his throat as Howard crammed a well-muscled arm into the blood pressure cuff with difficulty.

“Rocking chair. Y'know, little old granny, knitting, fireplace...never mind.” Howard inflated the cuff, listening briefly, then glanced at the meter. “Point is, numbers are much less meaningful unless I have a frame of reference to compare against. Captain America is not a previously established frame of reference, y'know?”

Steve frowned at him, still caught up in the rocking chair. It took entirely too long for him to picture the item in question, and when he finally did, the frown became a scowl. An attempted scowl, anyway. His eyes kept twitching involuntarily from watching Howard's face to the ground, and it was a struggle to keep them open at all.

Howard sighed, taking his expression as further confusion. “You're doing fieldwork; I can't isolate the variable. It'd influence the results.” He checked Steve's pupils with a flashlight, and Steve flinched.

“Stop that!” he snapped, swatting at the light.

Howard yelped in response, and the flashlight went careening to the other end of the room and smashed a hole in the plaster.

The silence drew out for a moment. Howard cradled his hand, staring at Steve. Steve stared back with what he knew were puffy, bloodshot eyes, breathing hard.

“...sorry,” he mumbled finally. Sprained or broken? He couldn't tell. Either way, it'd swell pretty good. He wondered if it'd compare to the headache pounding in his skull.

Howard was looking at him warily, before shaking his head. “Okay, you can go. Take a nap in the back room, and report to Phillips for light duty.”

_Huh?_

“ _Go,”_ Howard repeated sharply. Steve lurched unsteadily to his feet for the exit.

Howard was mumbling as he passed him: “Day 12: Showing signs of aggression, irritability, memory lapses, inability to cooperate. Experiment terminated for safety purposes.”

He did not comprehend the words until he was drifting off.

 

_Subject is approximately 380% more resistant than the average human adult to the effects of electric shock. This data is subjected to a 15% greater margin of error as the subject's internal resistance was unable to be precisely obtained. Effects of electrocution are also affected by variables such as duration of contact and pathway through the body. For safety reasons, extensive study is not recommended._

 

“ _Ahhhhh - !!!”_

Howard killed the power, sprinted to the door, and managed to catch Steve just as the super soldier crumpled. The weight was too much for Howard, and he followed Steve to the floor in a tangled heap.

Howard scrambled free. “Hey – hey, Rogers? Still with me?” One hand yanked the previously-live wire from Steve's clenched hand as Howard quickly rolled him onto his side (tongues were a choking hazard, after all). His gloves were flung aside as he checked the soldier's pulse.

No pulse. Howard cursed fluently under his breath even as he began checking for breathing, his hand still on Steve's neck. It was expected, really – sustained ventricular contraction under high direct-current was _expected_ , it was _temporary_ , it was _supposed_ to be temporary, “goddamn it, Rogers - “ He wasn't breathing either, that was expected too, but all the same, “Goddamn it, Rogers, _breathe!_ ”

And _there_ – a throb, a second, and yes yes _yes_ he was right, the Serum made short(er) work of reversing muscle tetanus and Howard nearly whooped as Steve's pulse resumed, weak but steady and strengthening by the second. The respiratory tetanus should be reversing just like the cardiac – yes, _yes_ , there went a breath and Howard swallowed his own heart, which seemed to have jumped up into his throat.

“I'm not even the one with a live wire,” he muttered aloud, but it felt like he had been all the same. He wouldn't have survived the cardiac and respiratory arrest half as well as Steve did, though, and thank god Steve was Steve because where would America be if he'd killed the national icon?

Assured of Steve's survival, he turned Steve's hands over to inspect the damage, loosening the harmless lead wire from his other hand. Two angry burns were on his palms, one entry and one exit. He'd sprayed a little water on Steve's palms to lower the electrical resistance (and lower the voltage required); the palms were still a little damp and Steve's arms were warm from internal burns.

He glanced down at Steve, who was stunned but actually goddamned _conscious_ (of _course_ he was, it wasn't like he'd ran the circuit through Steve's _head_ ), if barely so. Howard let out a shaky laugh, sagging against Steve in relief.

“Let's just stop there, okay?” Howard suggested breathlessly, running his thumbs over the angry burn marks, and his restless mind was already composing the notes: _5,000V, DC, hand-to-hand circuit with 3 second contact. Electrical resistance estimated at 1,200 ohms. Experiment terminated for subject safety._

 

 

_Subject is highly resistant to toxins. Resistance is approximately 872% greater than an average human adult._

 

“So here's the thing. If you're immune to most drugs, you should be, at the very _least_ , highly resistant to toxins. Drug binds to a receptor, activates or deactivates it, produces an effect. Your body overrides that too quickly for you to feel much of the effect – you'd produce new non-bonded receptors, or destroy the foreign substance, or whatever.

“Same idea for toxins, except that they're not exactly tested for safety and efficacy, they're developed for maximum damage. So they'd ravage your body – anyone's body, really – until your body gets a chance to mop up the chemicals and damage, and in your case that's faster than most.” Howard looked up from his chemicals with a smirk. “You'd be mighty useful in chemical warfare, soldier.”

Steve cocked his head to one side, considered it. It made sense. Sort of. “So...what, we'd test my exposure time and reaction to various toxins?” That did not sound pleasant, particularly the 'various toxins' aspect. He had a fleeting mental image of being tossed into a snake pit, and shuddered.

“Ideally, yes, but this is not an ideal world and neither of us are afforded so much free time from our other tasks nowadays to fully emulate the scientific method.” Howard wrote a few notes, flipped some switches. “I have two in mind. We'll start with the one you're more likely to encounter. It's also far easier to obtain in adequate amounts.”

“What is it?”

Howard looked at Steve, and his smile didn't reach his eyes. “What'd you say your father died of again?”

“Mustard gas. He was in the 107th infantry, and they'd...oh.”

Howard was still looking at him, and when had his old sly grin manifested into something that looked so...weary, like he hated himself? “Still want to do this, Rogers?”

Steve took a deep breath, suddenly noticing the neighbouring room has its doors reoutfitted, the new seals visibly airtight. He smiled at Howard; it came out as a grimace. “It's okay. I trust you.”

“You probably shouldn't.”

He stepped forward anyway. For the first time since the Serum, it felt like all his heart palpitations has come back.

 

_Subject is approximately 265% less affected by temperature extremes than an average human adult. Data is incomplete for this parameter and requires further investigation._

 

“Captain,” Peggy was giving him that look again, the look that said _I've never met a more stupid man in my life_ , “exactly what are you doing?”

Steve flushed. Or he thought he did. His face felt perpetually hot, anyway. “Construction, ma'am. The bridge up ahead needs reinforcement before we can cross to the other bank.”

“I'm aware, Captain. I'm also aware of a notion called 'shifts', which you have soundly ignored.” She surveyed the sweat-soaked fatigues on his person with a crinkle of her nose. “Have you drank anything at _all_ today?”

“At mess,” Steve protested. She wasn't buying it. “After that contamination disaster yesterday, I might be better off not.”

“You look like a cooked shrimp,” she pronounced, somewhere between exasperation and disgust.

Steve tried for a smile. “Sunburn?”

Peggy did not deign to reply, but the glitter in her eyes promised that this was anything but over. Steve watched her leave, feeling a little weak in the knees.

 

“You're pushing yourself too hard.”

Steve looked over his shoulder to see Bucky scowling at him, and offered a faint smile in return. “Peggy sent you?”

Bucky ignored that. “Seriously, Steve, I know you have that newfangled Serum, but it's fucking 110 F outside and you've been at this for hours.” Bucky glared at him, the glare made slightly ineffective by his concern. “Do you know how awful you look right now?”

Steve shrugged, tried to mop his brow casually, and was faintly surprised by how dry his face was. “Water, contamination? Half the camp fighting for the latrine? It's catching up to me?”

“You're an awful liar, Rogers. I know you can't get sick.”

 _That_ made Steve pause. “How did you - “

“Well, I didn't _know_ , but I made a good guess.” Bucky's smile was just slightly triumphant before it slid off his face, brow creased with worry. “Look, Steve – I've known you most our lives, seen you come down with things I can't even name. Then you grew 6 inches and suddenly stop being allergic to everything under the goddamned sun. I'm pretty sure if you _could_ get sick, some of that TB or asthma or whatever would've shown up by now. I ain't Stark, but I also ain't fucking stupid.”

“The point is, Cap, just get your sorry ass back to camp so we don't have to stand out here,” called out Morita.

“We'll be here with you 'til you do, so you may as well spare us,” Falsworth added.

Steve turned; the rest of the Commandos had gathered, and when did they all sneak up on him? Sneaky bastards.

“Is this what they call an intervention?” he called out faintly as he saw Peggy approaching behind the men. She'd gone to recruit _backup_.

“Call it what you like, Captain,” she said, coming right into his face like she always did, and Steve actually backed up a step. “The point is,” another step, “we - “ And Steve lost his footing on the third step, pitching backwards; the world spun briefly before he felt a pair of strong arms under his shoulders and Bucky's voice shouting.

“Hell – he's burning up! Dugan, get the medics! Jones, Morita, help me carry him.”

“Hey, no – I'm just a little tired,” Steve protested, before the nausea finally overtook him and he threw up the rest of his lunch.

 

Howard told him the numbers much later, once he'd gotten them from the medics: it'd taken him 6 hours at something called the WBGT of 93.02 F for him to drop, after adjusting for relative exertion levels and the correlational nature of the study.

“Interestingly enough,” Howard said, as he passed him another water bottle, “you approach heat exhaustion faster than most. You sweat quicker and stay cooler than average until you begin to deplete your hydration reserves. Your core temperature then climbs, but you can still maintain that unsavoury state until you reach a core temperature of 113 F, which is well past when most men would've dropped from sunstroke.”

Steve wasn't sure how to respond to that. Was he supposed to express joy? He settled for just drinking his water instead, slow small sips.

Howard didn't seem to expect him to answer, just patted his shoulder. “Rest up, Cap – the last leg won't be for a while yet.”

 

 

 

They never got around to doing the tests for cold resistance. It had been the wrong season, at first, and when the weather began to cool there had been no time. Besides, by that point, data weren't half as important as _results;_ Schmidt and HYDRA had taken far higher priority than seeing how high he could jump.

When Steve woke up, 70 years later, and Fury told him that he'd been preserved in ice, it occurred to him that the government had gotten the results anyway, and for all of Howard's genius, on this his calculations had been very, very off.

**Author's Note:**

> I was really thrilled with this prompt, because this concept is something I'd seriously considered and have alluded to in other stories. Also, Steve and Howard didn't interact _that_ much in the film, and Howard scoured the ocean floor for him even after he was assumed dead; I wanted to give some background to what inspired that loyalty.
> 
> The 4x metabolism was taken from the Captain America movie. Other stats, where available, were taken from the Wikipedia excerpt on Captain America. All medical symptoms and knowledge are as accurate as I can make them. The WBGT (wet bulb globe temperature) index was actually not developed until 1956, well past Steve's hibernation date, but I figured it ought to have been fairly easy for Howard to develop such a thing (another reason why I used him for this purpose).


End file.
